Folding door



A. T. GARUBO FOLDING DOOR Sept. 7, 1954 2 Sheets-Sheet 1 Filed March 27,1951 FIG! INVENTOR ANGELO T. GARUBO ATTORNEY Sept. 7, 1 A. T. GARUBO2,688,365

FOLDING DOOR Filed March 27, 1951 2 Sheets-Sheet 2 INVENTOR ANGELO T.GARUBO maxi, ATTORNEY Patented Sept. 7, 1954 UNITED STATES l TENT OFFICEFOLDING DOOR Angelo .T. Garubo, Newark, N. J.

Application March 27, 1951, Serial No. 217,753

a 1 This invention relates to improvements in folding doors, windows,and the like, of a kind comprising a number of elongated panels havingtheir corresponding ends moVa-bly interconnected by a pantograph, rorlazy-tong, arrangement whereby *for folding they can be closely nestedtogether to one side of an opening with their surfaces coextensive andparallel to each other, or for unfolding they can be extended inedgeto-edge succession across the opening. More particularly, it relatesto improvements in folding doors, partitions, and the like, which aredisclosed U. S. Patent 2;5 7l7;8'84 which issued to me on December 1-1,1951.

The expression, folding closure-portion, will heused in the presentapplication as a generic term intended to include told-ing doors,windows, sections of 'walls, sections of ceilings and the like.

Certain disadvantageslimit the usefulness of prior-art types :of theclosure-portions under :consideration. For example, unless theirpantograph connected panels are unusually narrow, then, whenever thesepanels are nested, their respective edges extend beyond the two surfacesof the wall, ceiling, or the like, in which they are installed (:seeFig. 7 of the above-mentioned S. patent"). In the case of :a foldingwindow this will preclude the mounting of an insect- ;screen flush withthe outside surface of its frame in the usually preferred manner.

Another disadvantage is that it has been difzficul't to weather-stripthe :ends of the closureportion at which its panels are pantogr-ap hconnected.

'It is an object :of this invention to improve closure portions so :asto eliminate these and other disadvantages.

The principal improvement of the present inmention :is accomplished bymodifying the priornrt way of attaching each of the pantographconnectedpanels of the closure-portion to the stationary frame which it is to beinstalled. In the prior :art the required attachment (rotatable and:slidable) of each of the panels to adiaacent stationary structures,such as to the top and bottomof :a door if-rame, has :heen efiected atpivots which protrude from the LEHGS of the panel along a longitudinalaxis at for near the center line of the panel. According to the presentinvention it is efiected at pivots which protrude from the ends of thepanel along such an axis' 'a-t or near an edge of the panel.

Ari additional improvement is accomplished by modifying the basicgeometry of the pantographs 6 Claims. (Cl. 160-201) or lazy-tongs fromthat used in the prior art so that the succession of collapsibleparallelograms defined by their pivot-connected links are no longernecessarily equilateral. As a result the "panels of a closure-portioncan be made to nest (to one side of the opening in which they areinstalled) at any of a variety of desired angles with respect to theplane of the opening rather than necessarily at right angles thereto.

In the drawing:

Figure 1 represents a front elevation of the outside of a :foldingwindow embodiment of the invention with part of the external trimremoved to show underlying structure;

Figure 2 is a sectional View of a window of the kind shown in Figure 1taken along the line 2-,2 therein;

Figure 3 is a fragmentary view of another embodiment showing howlazy-tong pivots may be positioned in the ends of the panels .50 that afree set of lazy tong links joining the panels may be shorter than thepanel edges serving as the other set to produce a modified pantographaccording to the present invention.

Figure 4 is a fragmentary sectional view of 'a modification of thewindow of Figure 2 illustrating its adaptability to weather stripping;

Figure :5 is a large-scale isometric View of a small portion of thewindow of Figure *2 to show details thereof which cannot be .shown inthat figure because of its small scale;

Figure '6 shows a pantograph for use with a specific kind of pivot-track(or guideway') and how it may be used for an embodiment of the kindshown in Figure 3 to permit one panel to have certain .of its pivotscentered with respect to its thickness dimension while all of the othercorresponding pivots used for pantograph interconnecting the panels areoff-center.

Figure '7 shows the specific track or guideway "with which thepantograp'h of Figure 8 is to be used; and

Figure 8 is a schematic representation of an embodiment like that ofFigure '3 to show how the direction of tilt of the nested panels can bereversed from that shown in Figure 6 by using as anchor pivots the endpivots of the two free lazy tong links at the anchored end-of thepantograph rather than corresponding edge pivots in the panel at thatend.

The window shown in Figures 1 and 2 is set in frame Hi and comprisesthree panels H, l2, and 13. The panels I i-l3 are supported in a manner,which is to be described below, so that the panels can be raisedtogether to a nesting position near the top of the window opening. Themechanism provided for this purpose operates in such a manner that asthe bottom panel is drawn upward, as shown at 15 in Figure 2, each ofthe panels will rotate in a clockwise direction, for the orientationshown in Figure 2, about a longitudinal axis which extends along thepanel near its lower edge, whereby its top edge will tilt backward asshown by arcuate arrows B. At the same time the lower edge of each panelwill move upwardly as shown by arrows U. The relative rates of therotational and upward movements will be such that each panel will moveupward as a whole. As a result, the panels I l-l3, in any positionsintermediate their extreme positions for the fully closed or fullyopened conditions of the window, will slope downward, toward theout-of-doors. Therefore they will serve to deflect upward any inwardlymoving air drafts, and any driven rain which strikes them will rundownward and outward to fall harmlessly upon the outer edge of thewindow sill 16. Moreover, no part of any of the panels will everprotrude beyond the front edge I! of the Window frame l0. Because ofthis last fact an insect screen may be flush-mounted on the outside offrame In without impeding the operation of the window or beingsusceptible to being damaged by it. However, since the top edges of thepanels do move inwardly, proper precautions must be taken in so far asthe positioning of any appurtenances which may be attached to the insideof the window. For example, a valance 28 should not extend downwardbelow the arcuate path followed by the top edge of the top panel [3 inopening the window.

There is generally represented in Figure 1 at l8 the pantographmechanism for movably interconnecting panels lI-I3 and causing them tooperate together. The details of the pantograph arrangement l8 cannot beshown in this figure because of its small scale. However, in it aguideway 19, in which a number of pivots of the pantograph l8 arerotatably and slidably supported, is large enough to be recognizable inthis figure. The ends of the guideway l9 are partially cutaway to showhow a metal strap is carried within the guideway and is connected to thebottom-edge pin 2| of the bottom panel H. The strap 20 is thin enough sothat it occupies little of the space inside of the guideway I9 andtherefore does not interfere with its function of supporting and guidingcertain of the pivots for the pantograph [8. In order to reach andengage the end of the strap 20 while the strap is closely adjacent theback inside surface of the guideway [9 the pin 2! is made longer thanthe other pins of the pantograph. Shortly beyond the point where thestrap 20 emerges from the top end of the guideway l9 it passes over apulley 23 and extends downward to a counterweight 24. It is to beunderstood that a similar counterweighing arrangement is built into theleft side of the window even though it cannot be seen inasmuch as theframe is not shown to be cut away on its left side. The weight 24 shouldbe heavy enough so that the only force required to nest or extend thepanels is that needed to overcome the cumulative friction of the variouspivots and links employed in the two pantographs l8. It will be foundthat this friction will suffice to hold the panels in any of theirpositions intermediate fully nested or fully extended if the weights 24are properly selected to exactly counterbalance the dead weight of thepanels.

The details of the control mechanism used along each side of the foldingwindow for movably interconnecting the panels ll-l3 appear most clearlyin Figures 3, 6, 'I and 8. In general this mechanism comprises (I) apantograph I8, (II) a guide-way I9, and (III) an anchoring socket 34.Each of the pantographs is made up of (l) a set of free links 30, (2) aset of pane links 3| (by a panel link, as that term is used herein, ismeant either an actual link which is fastened to and along an end-edgeof a panel or simply an end-edge of a panel which itself serves as alink. Moreover, according to the present invention, the panel links maybe either of the same length as the free links or of a differentlength), (3) a number of center pivots 32 each rotatably joining thecenter of a "free link with the center of a panel link, and (4) a numberof end pivots 33 each rotatably joining the end of a free link with theend of a panel link. All of the end pivots 33 which are located on agiven side of each pantograph l8 have extensions for holding theassembly operably captive in the frame Ill. To this end these extensionsof all but one of the end pivots 33 of each pantograph are adapted to beretained within and guided along a respective guide-way IS, theextension of that one pivot 33 of each pantograph [8 being adapted to berotatably captive in a respective anchoring socket 34. Thus eachguide-way I9 will have the extensions of appropriate ones of the endpivots 33 caught captive between its guiding surfaces 25 and 26 whileits associated anchoring socket 34 will have the extension of anappropriate single one of the end pivots 33 held rotatively captive init. In this arrangement, as distinguished from many arrangements of theprior art including those described in my above-mentioned U. S.patent,'the guide pivots of each pantograph are end pivots instead ofcenter pivots. As a result no part of any of the panels I l-l3 can moveoutwardly during opening of the window and. thus one of thedisadvantages of the prior art, that of interference with exteriorinsect netting, screens, storm windows, etc., is eliminated.

Moreover, as another result of this kind of movement it is possible touse a weather strip arrangement like that shown in Figure 5 at 35, 36.In this arrangement one fixed grooved element 35 for each end-edge of Ieach panel is mounted in the frame II] with its groove facing inwardlywhile one conjugately-shaped edge piece 36, is carried along the outsidesurface of each endedge of each panel with a tongue positioned to engagethe groove in an element 35 when the window is closed. As a result ofusing pantographs which are guided by end pivots rather than centerpivots, i. e., as a result of using pantographs like those shown herein,each entire window panel moves forward as a whole and therefore thistypeof weather stripping ar rangement is rendered feasible, whereas it wouldnot be feasible if the panel were controlled by a conventionalcenter-pivot-guided pantograph, since in that case half of the panelwould move in the direction to disengage the tongued element from thegrooved one at the same time that its other half would be moving in thedirection to engage them. Thus another disadvantage of the prior art iseliminated.

The dimensions D and d shown in Figure 3 for the panel links 3| and thefree links 32 are unequal, the dimension D being the larger in thisparticular example.

it is possible to attain the following :by using free and panel links ofunequal lengths:

The panels can be made to tilt in direction toward which the panels are:moved for nesting them by making the free links the shorter while anend pivot of a free .as the anchor pivot of a pantograph orzby makingthe :free links the longer whiie using an edge pivot of a panel link asthe anchor; or the panels can be made to tilt in the direction oppositeto that in which the panels are moved for :nesting them by doing theconverse, i. :.e :by makzmg the me the s'hmter while using edge pivot ofa panel link longer while using an end pivot of a .free link as I theanchor.

The type of relative movement which is imparted to the panels l1|-|13lay the pantograph 1:8

also facilitates weather stripping of the :top and bottom edges of thepanels. Two ways of adapting these edges for interlocking tightly whenthe window is closed are shown in Figures 2 and 5 on the one and .Figure4 on the other. In the first of these two ways the juxtaposed edges ofadjacent panels are ship-lapped so that when the window is closed thereis no straight line opening between them through which light wind, ,orrain can directly penetrate. Each two cooperating ship-lapped edges comefirmly together because of the fact that while the lower of the twoedges, i, e., the top edge of the lower of two adjacent panels, movesoutward, the upper one, i. e., the bottom edge of the upper panel, movesdirectly downward. As a result, at the very last part of the closingcycle the bottom edge of the upper one of each adjacent pair of panelsmoves directly downward upon the top edge of the panel beneath it andthis closes the space between them. In the second of these ways, seeFigure 4, interlocking metal window stripping is added to the bottom andtop edges of each panel as shown at 3! and 38. The use of such strippingis advantageous for the following reasons: (1) they will provide bettersliding surface; (2) they will permit the use of more complexinterlocking joints since thin sections, such as tongues and grooveswill be less prone to break or Warp when made of metal; and (3) metalstripping may be made resilient, e. g., in acordance with the prior artpractice of fastening the strip along only one of its edges and springloading it to bend slightly outr ward away from the underlying paneledge.

Figure '7 shows how the track 19 may be made to deviate slightly from astraight axis in a terminal portion 39 near its end at which thepantograph is anchored to permit a slight modification in thepositioning of the anchor pivot in the edge of the anchored panel. lhepivot in question is positioned midway between the two surfaces of theanchored panel so that its edge near to its anchored axis of rotationmay be rounded as shown at 4!]. It is sometimes desirable to round thisedge so that the clearance between it and the adjacent side of the framein which it is mounted will remain constant as the anchored panel isrotated. However, since all of the edge pivots 33 of the panel links arepositioned nearer to one surface of the panels than the other in orderto make possible the use of free and panel links of difierent lengths,such center positioning of the anchor pivot will cause the entiremechanism to bind as the panels are moved toward their nested condition.In other words with center positioning of the anchor pivot the anchorsocket 34 must be misaligned with the guideway [9 to attain properalignment of the panel surfaces when the window or door is closed.However, when the guideway is bent in the manner shown herein, binding"is averted and, if the length of the terminal portion .39 is no greaterthan the width of one panel, the surfaces of all of the panels will beproper .alignmentwhen the closure portion is fully closed.

The juxtaposed edges of adjacent panels may he formed either to permitthe panels to come into the coplanar relationship as shown in Figure4-01 into the lapped relationship shown in Figure .2.

What is claimed is:

l. A folding closure portion comprising 2, rectangiilar frame; withinthe frame a plurality of elongated panels at least two of which are ofthe "same width; a pair :of pantograph means tolda'blyand-u-n-foldablyinterconnecting the panels along their opposite end-edges; a pair ofguideway means mounted in said frame facing each other across theopening surrounded thereby for carrying the interconnected panelsslidably in said frame along a path parallel to a pair of opposite sidesof the frame; each of said pantograph means comprising a set offree-links of a first predetermined length and a set of means acting aspanel-links of a predetermined "length different than said first length'ar-ticulate'ly joined by center pivots andend pivots in a lazy-tongarrangement, each of the center pivots being positioned so that anextension of its axis will pass between the thickness boundaries of arespective panel in any position thereof, a number of the end pivotswhich are positioned in each lazy-tong arrangement along one of itssides having portions which extend between guiding surfaces of theguideway means and are rotatably and slidably captive therebetween,whereby each of the panels in its entirety will tilt away from the planeof the opening defined by said frame as the panels are progressivelyfolded together to open the closure portion; and weather stripping meanscomprising for each end-edge of each panel, an element, fixed in saidframe, which has its surface which faces in the direction toward whichthe panel is tiltable formed with a predetermined interlockingconfiguration, and a surface on said end-edge having a conjugateconfiguration for tightly engaging that of the fixed element when theclosure portion is fully closed.

2. A folding closure portion as in claim 1 also comprising an anchormeans for each pantograph means, each anchor means having a socketaligned with one of said slots for anchoring the pantograph means sothat a predetermined one of said panels can be made to rotate withoutsliding while each of the others simultaneously rotates and slides; andan anchor end pivot on the same side of the lazy tong arrangement as itssaid end pivots which are captive in said one guideway, said anchorpivot being an end pivot of the panel-link means of said predeterminedpanel and having a portion which extends into said socket and isrotatably captive therein.

3. A folding closure portion as in claim 2 in which all of the endpivots but the anchor end pivots are positioned in alignment with axeswhich extend parallel and near to respective ones of the long sides ofthe panels and are off-center with respect to the thickness boundariesthereof, while said anchor pivots are positioned in alignment with anaxis which extends similarly with respect to one of the long sides ofsaid predetermined panels but is substantially centered between itsthickness boundaries, each of said slots is rectilinear over most of itslength but for an end portion which deviates from the axis of therectilinear portion by a predetermined fraction of the thickness of saidpredetermined panel, and

.each of said sockets is aligned with the end of guideways positionedwith their slots facing each other and adapted to carry theinterconnected panels slidably along the axis of the slots; each of saidpantograph means comprising a set of free-links of a predetermined firstlength and a set of means acting as panel-link of a predetermined lengthdifferent than said first length, such as end-edges of the panels oractual panel-links .25

attached respectively therealong, articulately joined by center pivotsand end pivots in a lazytong arrangement, each of said center pivotsbeing positioned in each lazy tong arrangement in alignment with alongitudinal axis of a respective panel which axis is parallel to thelong sides of the panel and is located substantially midway between thelong sides and also the thickness boundaries of the panel, and for eachlazy tong arrangement a number of the end pivots which are positionedalong one of its sides having portions which extend into the slot of arespective one of the guideways and are rotatably and slidably captivetherein; a rectangular frame surrounding said interconnected panels andcarrying said guideways; and means, including fixed elements mounted onsaid frame and movable elements mounted on the edge-ends of said panels,for weather-stripping the end-edges of the panels.

6. A folding closure portion as in claim 5 in which the pairs of edgesof the long sides of adjacent panels which are juxtaposable by unfoldingthe closure portion are provided with interlocking surfaces forweather-stripping the closure portion when it is closed.

References Cited in the file Of this patent UNITED STATES PATENTS NumberName Date 702,146 McCloud June 10, 1902 765,196 Ritter July 19, 19041,495,589 Hofiman May 27, 1924 1,892,340 Guth Dec. 27, 1932 1,933,709Cooper Nov. 7, 1933

